Protein-calorie malnutrition (PCM) in Egypt immunological changes of salivary protein in PCM

The immune system in children with malnutrition--a systematic review

BACKGROUND

Malnourished children have increased risk of dying, with most deaths caused by infectious diseases. One mechanism behind this may be impaired immune function. However, this immune deficiency of malnutrition has not previously been systematically reviewed.

OBJECTIVES

To review the scientific literature about immune function in children with malnutrition.

METHODS

A systematic literature search was done in PubMed, and additional articles identified in reference lists and by correspondence with experts in the field. The inclusion criteria were studies investigating immune parameters in children aged 1-60 months, in relation to malnutrition, defined as wasting, underweight, stunting, or oedematous malnutrition.

RESULTS

The literature search yielded 3402 articles, of which 245 met the inclusion criteria. Most were published between 1970 and 1990, and only 33 after 2003. Malnutrition is associated with impaired gut-barrier function, reduced exocrine secretion of protective substances, and low levels of plasma complement. Lymphatic tissue, particularly the thymus, undergoes atrophy, and delayed-type hypersensitivity responses are reduced. Levels of antibodies produced after vaccination are reduced in severely malnourished children, but intact in moderate malnutrition. Cytokine patterns are skewed towards a Th2-response. Other immune parameters seem intact or elevated: leukocyte and lymphocyte counts are unaffected, and levels of immunoglobulins, particularly immunoglobulin A, are high. The acute phase response appears intact, and sometimes present in the absence of clinical infection. Limitations to the studies include their observational and often cross-sectional design and frequent confounding by infections in the children studied.

CONCLUSION

The immunological alterations associated with malnutrition in children may contribute to increased mortality. However, the underlying mechanisms are still inadequately understood, as well as why different types of malnutrition are associated with different immunological alterations. Better designed prospective studies are needed, based on current understanding of immunology and with state-of-the-art methods.

Comparative proteomic analysis of human whole saliva of children with protein-energy undernutrition

OBJECTIVE

The aim of the present study was to investigate the protein profile of children with different levels of protein-energy undernutrition (PEU) through a proteomic approach of human whole saliva.

METHODS

Initially, saliva samples of children with mild, moderate, and severe PEU were collected and lyophilized. Saliva samples of healthy children were used as controls. Samples were analyzed for total protein using the Bradford method. Saliva samples were analyzed by two-dimensional electrophoresis according to their isoelectric point (pI) and their molecular weights (MWs).

RESULTS

Comparisons of protein bands among the healthy and mildly, moderately, and severely undernourished children showed significant differences in the MWs (P = 0.001) and pI values (P = 0.03). In total 159 spots were identified in the healthy children; 156, 168, and 221 spots were observed in mildly, moderately, and severely undernourished children, respectively. Mildly undernourished children presented with the spot with the highest MW of 293 kDa (pI = 7.77) and the lowest MW of 5 kDa (pI = 4.83). Moderately undernourished children were the only ones who did not present with a protein band with an MW of 30 kDa. The presence of a protein band with an MW of 123 kDa (pI = 516), possibly a cyclin-dependent protein kinase, was also observed only in this group.

CONCLUSION

The protein profile in saliva varies according to the presence or absence of PEU, and these variations are specifically expressed in different grades of undernutrition. Thus, saliva may be an important diagnostic tool for the assessment of PEU.

Desnutrição energético-protéica e cárie dentária na primeira infância

Este estudo tem por objetivo investigar a relação existente entre a desnutrição energético-protéica e a cárie dentária precoce na primeira infância. Trata-se de uma comunicação, para a qual foi realizada uma revisão da literatura, a partir de análise documental de produção bibliográfica, baseada em levantamentos de periódicos e consultas a livros. Verificou-se que a cárie precoce na infância é altamente prevalente nas comunidades de baixa renda, nas quais a desnutrição é um fator comum e de grande relevância. Estudos mostram que crianças desnutridas tendem a apresentar defeitos estruturais no esmalte do dente, como também estão predispostas a um maior risco à cárie dentária. Portanto, uma deficiência energético-protéica durante a fase de desenvolvimento dentário (odontogênese) tem demonstrado uma maior suscetibilidade à cárie dentária, atraso na cronologia de erupção e defeitos estruturais do esmalte (hipoplasia de esmalte), hipofunção das glândulas salivares e mudança na composição da saliva. Estes fatores podem ser os mecanismos pelos quais a desnutrição associa-se à cárie. Em conclusão, os estudos sugerem que a deficiência energético-protéica durante a odontogênese gera atraso na cronologia de erupção e defeitos estruturais no esmalte (hipoplasia), além de poder afetar as glândulas salivares, aumentando o risco de ocorrência da doença cárie. Estudos investigando associações entre desnutrição e cárie na primeira infância são de grande relevância para ampliar o conhecimento desta doença e o desenvolvimento de ações de promoção e de prevenção desse problema de saúde pública com aplicações nas áreas de nutrição e odontologia.